An outbreak of SARS-CoV-2 in a public-facing office in England.

BACKGROUND: An outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with an attack rate of 55% (22/40 workers) occurred at a public-facing office in England from August to September 2021. Published evidence regarding outbreaks in office workplaces remains limited. AIMS: To describe an investigation of workplace- and worker-related risk factors following an outbreak of SARS-CoV-2 in a public-facing office. METHODS: The COVID-19 (coronavirus disease 2019) Outbreak Investigation to Understand Transmission (COVID-OUT) study undertook an investigation of the outbreak. This included surface sampling, occupational environmental assessment, molecular and serological testing of workers, and detailed questionnaires. RESULTS: Despite existing COVID-19 control measures, surface sampling conducted during a self-imposed 2-week temporary office closure identified viral contamination (10/60 samples, 17% positive), particularly in a small, shared security office (6/9, 67% positive) and on a window handle in one open-plan office. Targeted enhanced cleaning was, therefore, undertaken before the office reopened. Repeat surface sampling after this identified only one positive (2%) sample. Ventilation was deemed adequate using carbon dioxide monitoring (typically ≤1000 ppm). Twelve workers (30%) responded to the COVID-OUT questionnaire, and all had been vaccinated with two doses. One-third of respondents (4/12) reported direct physical or close contact with members of the public; of these, 75% (3/4) reported a divider/screen between themselves and members of the public. CONCLUSIONS: The results highlight the potential utility of surface sampling to identify SARS-CoV-2 control deficiencies and the importance of evolving, site-specific risk assessments with layered COVID-19 mitigation strategies.

Hazard Group 3 agent decontamination using hydrogen peroxide vapour in a class III microbiological safety cabinet.

AIMS: This study investigated the efficacy of hydrogen peroxide vapour (HPV) at inactivating hazard group 3 bacteria that have been presented dried from their growth medium to present a realistic challenge. METHODS AND RESULTS: Hydrogen peroxide vapour technology (Bioquell) was used to decontaminate a class III microbiological safety cabinet containing biological indicators (BIs) made by drying standard working suspensions of the following agents: Bacillus anthracis (Ames) spores, Brucella abortus (strain S99), Burkholderia pseudomallei (NCTC 12939), Escherichia coli O157 ST11 (NCTC 12079), Mycobacterium tuberculosis (strain H37Rv) and Yersinia pestis (strain CO92) on stainless steel coupons. Extended cycles were used to expose the agents for 90 min. The HPV cycle completely inactivated B. anthracis spores, B. abortus, B. pseudomallei, E. coli O157 and Y. pestis when BIs were processed using quantitative and qualitative methods. Whilst M. tuberculosis was not completely inactivated, it was reduced by 4 log10 from a starting concentration of 106 colony-forming units. CONCLUSIONS: This study demonstrates that HPV is able to inactivate a range of HG3 agents at high concentrations with associated organic matter, but M. tuberculosis showed increased resistance to the process. SIGNIFICANCE AND IMPACT OF THE STUDY: This publication demonstrates that HPV can inactivate HG3 agents that have an organic load associated with them. It also shows that M. tuberculosis has higher resistance to HPV than other agents. This shows that an appropriate BI to represent the agent of interest should be chosen to demonstrate a decontamination is successful.

Drumming-associated anthrax incidents: exposures to low levels of indoor environmental contamination.

Two fatal drumming-related inhalational anthrax incidents occurred in 2006 and 2008 in the UK. One individual was a drum maker and drummer from the Scottish Borders, most likely infected whilst playing a goat-skin drum contaminated with Bacillus anthracis spores; the second, a drummer and drum maker from East London, likely became infected whilst working with contaminated animal hides.We have collated epidemiological and environmental data from these incidents and reviewed them alongside three similar contemporaneous incidents in the USA. Sampling operations recovered the causative agent from drums and drum skins and from residences and communal buildings at low levels. From these data, we have considered the nature of the exposures and the number of other individuals likely to have been exposed, either to the primary infection events or to subsequent prolonged environmental contamination (or both).Despite many individual exposures to widespread low-level spore contamination in private residences and in work spaces for extended periods of time (at least 1 year in one instance), only one other individual acquired an infection (cutaneous). Whilst recognising the difficulty in making definitive inferences from these incidents to specific residual contamination levels, and by extending the risk to public health, we believe it may be useful to reflect on these findings when considering future incident management risk assessments and decisions in similar incidents that result in low-level indoor contamination.

Sampling and inactivation of wet disseminated spores from flooring materials, using commercially available robotic vacuum cleaners.

AIMS: Four commercially available robotic vacuum cleaners were assessed for sampling efficiency of wet disseminated Bacillus atrophaeus spores on carpet, polyvinyl chloride (PVC) and laminate flooring. Furthermore, their operability was evaluated and decontamination efficiency of one robot was assessed, using a sodium hypochlorite solution. METHODS AND RESULTS: In an environmental chamber, robots self-navigated around 4 m2 of flooring containing a single contaminated 0·25 m2 tile (c. 104 spores per cm2 ). Contamination levels at predetermined locations were assessed by macrofoam swabs (PVC and laminate) or water soluble tape (carpet), before and after sampling. Robots were dismantled postsampling and spore recoveries assessed. Aerosol contamination was also measured during sampling. Robot sampling efficiencies were variable, however, robots recovered most spores from laminate (up to 17·1%), then PVC and lastly the carpet. All robots spread contamination from the 'hotspot' (all robots spread <0·6% of the contamination to other areas) and became surface contaminated. Spores were detected at low levels during air sampling (<5·6 spores per litre). Liquid decontamination inactivated 99·1% of spores from PVC. CONCLUSIONS: Robotic vacuum cleaners show promise for both sampling and initial decontamination of indoor flooring. SIGNIFICANCE AND IMPACT OF THE STUDY: In the event of a bioterror incident, e.g. deliberate release of Bacillus anthracis spores, areas require sampling to determine the magnitude and extent of contamination, and to establish decontamination efficacy. In this study, we investigate robotic sampling methods against high concentrations of bacterial spores applied by wet deposition to different floorings, contamination spread to other areas, potential transfer of spores to the operators and assessment of a wet vacuum robot for spore inactivation. The robots' usability was evaluated and how they can be employed in real life scenarios. This will help to reduce the economic cost of sampling and the risk to sampling/decontamination teams.

Is there an infection risk when playing drums contaminated with Bacillus anthracis?

AIMS: This study aims to investigate the aerosol release of a Bacillus anthracis spore surrogate from two different types of drums while playing, by; (i) quantifying the number of spores aerosolized during playing; (ii) investigating spore recovery from drums over long time periods, and (iii) measuring differences between (i) and (ii) for two different drums types. METHODS AND RESULTS: Two African drums were contaminated with Bacillus atrophaeus spores then sampled and played by hand over a number of days. During playing three air samplers were used to collect any aerosols generated, the choice of air samplers (Casella slit sampler, all glass impinger and six-stage Andersen sampler) allowed for characterization of the aerosols produced. CONCLUSIONS: Spore contamination of drums was found to be long-lasting with a small percentage of the spores being detached and aerosolized during drumming. The results of these studies have been used for a quantitative risk assessment of playing drums contaminated with B. anthracis spores. SIGNIFICANCE AND IMPACT OF THE STUDY: This demonstrates that the risk of inhalational exposure while playing drums contaminated with the levels linked to the US and UK cases is very low and that the resulting cases of inhalational anthrax can be explained by being unusual events involving highly susceptible persons.

Whispering gallery mode diamond resonator.

We demonstrate a nearly spherical diamond whispering gallery mode resonator with quality factor (Q factor) Q=2.4×10(7) limited by material loss approaching α=4×10(-3) cm(-1). The Q factor does not depend on the wavelength: it is approximately the same at 1319 and 1550 nm. Resonators with this range of Q (<10 MHz at 1550 nm wavelength) are attractive for laser locking and stabilization. Applications such as stable compact optical comb generators as well as Raman optical frequency shifters will be feasible with further improvement of the material.

Low-temperature decontamination with hydrogen peroxide or chlorine dioxide for space applications.

The currently used microbial decontamination method for spacecraft and components uses dry-heat microbial reduction at temperatures of >110°C for extended periods to prevent the contamination of extraplanetary destinations. This process is effective and reproducible, but it is also long and costly and precludes the use of heat-labile materials. The need for an alternative to dry-heat microbial reduction has been identified by space agencies. Investigations assessing the biological efficacy of two gaseous decontamination technologies, vapor hydrogen peroxide (Steris) and chlorine dioxide (ClorDiSys), were undertaken in a 20-m(3) exposure chamber. Five spore-forming Bacillus spp. were exposed on stainless steel coupons to vaporized hydrogen peroxide and chlorine dioxide gas. Exposure for 20 min to vapor hydrogen peroxide resulted in 6- and 5-log reductions in the recovery of Bacillus atrophaeus and Geobacillus stearothermophilus, respectively. However, in comparison, chlorine dioxide required an exposure period of 60 min to reduce both B. atrophaeus and G. stearothermophilus by 5 logs. Of the three other Bacillus spp. tested, Bacillus thuringiensis proved the most resistant to hydrogen peroxide and chlorine dioxide with D values of 175.4 s and 6.6 h, respectively. Both low-temperature decontamination technologies proved effective at reducing the Bacillus spp. tested within the exposure ranges by over 5 logs, with the exception of B. thuringiensis, which was more resistant to both technologies. These results indicate that a review of the indicator organism choice and loading could provide a more appropriate and realistic challenge for the sterilization procedures used in the space industry.

Probability of clinically significant hearing recovery following salvage intratympanic steroids for sudden sensorineural hearing loss in the 'real world'.

OBJECTIVE: This study aimed to determine the probability of hearing recovery in patients with idiopathic sudden sensorineural hearing loss following salvage intratympanic steroids. METHOD: A retrospective review of all patients receiving salvage intratympanic steroid injections for idiopathic sudden sensorineural hearing loss was performed (January 2014 to December 2019). Twenty-two patients were identified, of whom 15 met inclusion criteria. Pre- and post-treatment audiograms were compared with the unaffected ear. Hearing recovery was categorised based on American Academy of Otolaryngology Head and Neck Surgery criteria. RESULTS: Only 1 patient out of 15 (6.7 per cent) made a partial recovery, and the remainder were non-responders. The median duration of time between symptom onset and first salvage intratympanic steroid treatment was 52 days (range, 14-81 days). No adverse reactions were observed. CONCLUSION: 'Real world' patients with idiopathic sudden sensorineural hearing loss present differently to those in the literature. Sudden sensorineural hearing loss should be diagnosed with care and intratympanic steroid injections initiated early if considered appropriate. Patients should make an informed decision on treatment based on prognostic factors and local success rates.

Regulation of distinct stages of skeletal muscle differentiation by mitogen-activated protein kinases.

The signal transduction pathway or pathways linking extracellular signals to myogenesis are poorly defined. Upon mitogen withdrawal from C2C12 myoblasts, the mitogen-activated protein kinase (MAPK) p42Erk2 is inactivated concomitant with up-regulation of muscle-specific genes. Overexpression of MAPK phosphatase-1 (MKP-1) inhibited p42Erk2 activity and was sufficient to relieve the inhibitory effects of mitogens on muscle-specific gene expression. Later during myogenesis, endogenous expression of MKP-1 decreased. MKP-1 overexpression during differentiation prevented myotube formation despite appropriate expression of myosin heavy chain. This indicates that muscle-specific gene expression is necessary but not sufficient to commit differentiated myocytes to myotubes and suggests a function for the MAPKs during the early and late stages of skeletal muscle differentiation.

Avoidance of BIPP allergy hypersensitivity reactions following ear surgery.

Bismuth Iodoform Paraffin Paste (BIPP) is one of the most commonly used packs after middle and external ear surgery. Only two retrospective case studies exist which found a 0.4% and 6% overall risk of BIPP allergy. The result of our prospective patch testing study identifies the true incidence of BIPP allergy to be 12% in those previously exposed and 1% in those not previously exposed. The component part responsible is iodoform not iodine. We recommend patch testing patients previously exposed to BIPP undergoing ear surgery, if postoperative BIPP packing is being considered. We recommend those patients allergic to BIPP should be tested with its constituent parts for future reference. It is important to determine whether there is allergy to iodine solution or not as this would preclude them from future iodine solution contrast studies and iodine solution skin prep before surgery. We do not recommend testing patients not previously known to be exposed to BIPP as the incidence of allergy is low and there exists a risk of sensitization.

Hospital and community acquired infection and the built environment--design and testing of infection control rooms.

Negative-pressure isolation rooms are required to house patients infected with agents transmissible by the aerosol route in order to minimise exposure of healthcare workers and other patients. Housing patients in a separate room provides a barrier which minimises any physical contact with other patients. An isolation room held at negative pressure to reduce aerosol escape and a high air-change rate to allow rapid removal of aerosols can eliminate transmission of infectious aerosols to those outside the room. However, badly designed and/or incorrectly operating isolation rooms have been shown to place healthcare workers and other patients at risk from airborne diseases such as tuberculosis. Few standards are available for the design of isolation rooms and no pressure differential or air-change rates are specified. Techniques such as aerosol particle tracer sampling and computational fluid dynamics can be applied to study the performance of negative-pressure rooms and to assess how design variables can affect their performance. This should allow cost-effective designs for isolation rooms to be developed. Healthcare staff should be trained to understand how these rooms operate and there should be systems in place to ensure they are functioning correctly.

Epidermal growth factor receptor and the adaptor protein p52Shc are specific substrates of T-cell protein tyrosine phosphatase.

T-cell protein tyrosine phosphatase (TCPTP) exists as two forms generated by alternative splicing: a 48-kDa endoplasmic reticulum (ER)-associated form (TC48) and a 45-kDa nuclear form (TC45). To identify TCPTP substrates, we have generated substrate-trapping mutants, in which the invariant catalytic acid of TCPTP (D182) is mutated to alanine. The TCPTP D182A substrate-trapping mutants were transiently overexpressed in COS cells, and their ability to form complexes with tyrosine-phosphorylated (pTyr) proteins was assessed. No pTyr proteins formed complexes with wild-type TCPTP. In contrast, TC48-D182A formed a complex in the ER with pTyr epidermal growth factor receptor (EGFR). In response to EGF, TC45-D182A exited the nucleus and accumulated in the cytoplasm, where it bound pTyr proteins of approximately 50, 57, 64, and 180 kDa. Complex formation was disrupted by vanadate, highlighting the importance of the PTP active site in the interaction and supporting the characterization of these proteins as substrates. Of these TC45 substrates, the approximately 57- and 180-kDa proteins were identified as p52Shc and EGFR, respectively. We examined the effects of TC45 on EGFR signaling and observed that it did not modulate EGF-induced activation of p42Erk2. However, TC45 inhibited the EGF-induced association of p52Shc with Grb2, which was attributed to the ability of the PTP to recognize specifically p52Shc phosphorylated on Y239. These results indicate that TC45 recognizes not only selected substrates in a cellular context but also specific sites within substrates and thus may regulate discrete signaling events.

Multiple requirements for SHPTP2 in epidermal growth factor-mediated cell cycle progression.

Using transient overexpression and microinjection approaches, we examined SHPTP2's function in growth factor signaling. Overexpression of catalytically inactive SHPTP2 (PTP2CS) but not catalytically inactive SHPTP1, inhibited mitogen-activated protein (MAP) kinase activation and Elk-1 transactivation following epidermal growth factor (EGF) stimulation of 293 cells. An SHPTP2 mutant with both C-terminal tyrosyl phosphorylation sites converted to phenylalanine (PTP2YF) was also without effect; moreover, PTP2YF rescued PTP2CS-induced inhibition of EGF-induced Elk-1 transactivation. PTP2CS did not inhibit transactivation by activated Ras, suggesting that SHPTP2 acts upstream of or parallel to Ras. Neither PTP2CS nor PTP2YF inhibited platelet-derived growth factor (PDGF)-induced Elk-1 transactivation. Thus, protein-tyrosine phosphatase activity, but not tyrosyl phosphorylation of SHPTP2, is required for the immediate-early responses to EGF but not to PDGF. To determine whether SHPTP2 is required later in the cell cycle, we assessed S-phase entry in NIH 3T3 cells microinjected with anti-SHPTP2 antibodies or with a glutathione S-transferase (GST) fusion protein encoding both SH2 domains (GST-SH2). Microinjection of anti-SHPTP2 antibodies prior to stimulation inhibited EGF- but no PDGF- or serum-induced S-phase entry. Anti-SHPTP2 antibodies or GST-SH2 fusion protein could inhibit EGF-induced S-phase entry for up to 8 h after EGF addition. Although MAP kinase activation was detected shortly after EGF stimulation, no MAP kinase activation was detected around the restriction point. Therefore, SHPTP2 is absolutely required for immediate-early and late events induced by some, but not all, growth factors, and the immediate-early and late signal transduction pathways regulated by SHPTP2 are distinguishable.

Differential role of beta(1C) and beta(1A) integrin cytoplasmic variants in modulating focal adhesion kinase, protein kinase B/AKT, and Ras/Mitogen-activated protein kinase pathways.

The integrin cytoplasmic domain modulates cell proliferation, adhesion, migration, and intracellular signaling. The beta(1) integrin subunits, beta(1C) and beta(1A), that contain variant cytoplasmic domains differentially affect cell proliferation; beta(1C) inhibits proliferation, whereas beta(1A) promotes it. We investigated the ability of beta(1C) and beta(1A) to modulate integrin-mediated signaling events that affect cell proliferation and survival in Chinese hamster ovary stable cell lines expressing either human beta(1C) or human beta(1A). The different cytodomains of either beta(1C) or beta(1A) did not affect either association with the endogenous alpha(2), alpha(V), and alpha(5) subunits or cell adhesion to fibronectin or TS2/16, a mAb to human beta(1). Upon engagement of endogenous and exogenous integrins by fibronectin, cells expressing beta(1C) showed significantly inhibited extracellular signal-regulated kinase (ERK) 2 activation compared with beta(1A) stable cell lines. In contrast, focal adhesion kinase phosphorylation and Protein Kinase B/AKT activity were not affected. Selective engagement of the exogenously expressed beta(1C) by TS2/16 led to stimulation of Protein Kinase B/AKT phosphorylation but not of ERK2 activation; in contrast, beta(1A) engagement induced activation of both proteins. We show that Ras activation was strongly reduced in beta(1C) stable cell lines in response to fibronectin adhesion and that expression of constitutively active Ras, Ras 61 (L), rescued beta(1C)-mediated down-regulation of ERK2 activation. Inhibition of cell proliferation in beta(1C) stable cell lines was attributable to an inhibitory effect of beta(1C) on the Ras/MAP kinase pathway because expression of activated MAPK kinase rescued beta(1C) antiproliferative effect. These findings show that the beta(1C) variant, by means of a unique signaling mechanism, selectively inhibits the MAP kinase pathway by preventing Ras activation without affecting either survival signals stimulated by integrins or cellular interactions with the extracellular matrix. These findings highlight a role for beta(1)-specific cytodomain sequences in maintaining an intracellular balance of proliferation and survival signals.

Persistence of influenza on surfaces.

BACKGROUND: Close contact transmission (either direct or large droplet/droplet nuclei) is considered the main driver of influenza outbreaks but there is limited information regarding the role of fomites in transmission. AIM: To investigate the surface stability of influenza strains and thereby the role of fomites in transmission. METHODS: The viability and quantitative reverse transcription-polymerase chain reaction (qt-RT-PCR) signal of five influenza strains (A/PR/8/34/H1N1, A/Cal/7/09/H1N1, A/Cal/4/09/H1N1, A/Sol/54/06/H1N1, and A/Bris/59/07/H1N1) seeded on to three surfaces (cotton, microfibre, and stainless steel) were assessed over time. Coupons of material were seeded with 10µL of a 106-108pfu/mL suspension of cell culture-derived virus stock supplemented with 0.3% bovine serum albumin. Coupons were assayed by plaque assay and qt-RT-PCR at 1, 24h, and weekly for seven weeks using a vortex-mixing elution method. FINDINGS: Viable virus was detected from coupons for up to two weeks (stainless steel) and one week (cotton and microfibre), whereas detection of viruses by PCR was made for the entire seven-week study period. No strain differences were found. Ninety-nine percent reduction values (as a function of the seeding stock) were determined to be 17.7h for cotton (R2=0.86), 34.3h for microfibre (R2=0.80), and 174.9h for stainless steel (R2=0.98). CONCLUSION: Viable influenza was recovered from surfaces for up to two weeks. By contrast, influenza could be detected by PCR for more than seven weeks. These results have important implications for determining infection control protocols, cleaning regimes and sampling methods in healthcare settings.

Audit of specialist registrar training in tympanomastoid surgery for chronic otitis media.

BACKGROUND: A prospective audit of specialist registrars' (SRs') training in tympanomastoid surgery for chronic otitis media within the Anglia Regional Training Scheme is described. This audit recorded the surgical activity of the trainees and their contribution to operative procedures, and assessed the results of the procedures. This type of systematic approach to the audit of surgical training is important in light of the current shortened training programmes and increased accountability of trainers. OBJECTIVES: The study aimed to establish the levels of exposure to, supervision of and outcome of ear operations for chronic otitis media performed by ENT trainees in the East Anglia region. METHOD: A prospective, region-wide, minimum otology dataset-based proforma audit was undertaken, with compulsory SR participation. Proformas were completed at the time of operation (form one) and at a minimum interval of nine months post-operatively (form two). Data on form one included hospital, supervising consultant, name and training year of SR, contribution of SR (based on England Royal College of Surgeons guidelines interpreted by the SR), pre-operative audiology average (air conduction/bone conduction over 0.5, 1, 2 and 4 kHz), the pathology and the state of the ear at the time of surgery, and a breakdown of the procedure(s) undertaken. Form two recorded data relevant to form one as well as information regarding patient satisfaction and the operative result obtained, graded as 'gold' (no disease, dry ear and hearing average < 25 dB), 'silver' (two of these three) and 'bronze' (one of these three). All completed forms were analysed using Microsoft Access software. RESULTS: Completed copies of 409 form ones and 156 form twos were analysed. With advancing years, SRs' contributions to procedures increased without significant effect on the graded outcome, which appeared to be independent of SR year of training. Different regional hospitals were compared. Data collected also provided an otology training portfolio for SRs, forming part of their registrar in-training assessment (RITA). CONCLUSION: The East Anglia SR audit of SRs' training in tympanomastoid surgery for chronic otitis media was a powerful training tool. It demonstrated the safe progression of SR training in supervised ear surgery, with SRs' results being comparable to those for consultant-performed procedures.